Systematic review of risk prediction models for diabetes after bariatric surgery.

BACKGROUND: Diabetes remission is an important outcome after bariatric surgery. The purpose of this study was to identify risk prediction models of diabetes remission after bariatric surgery. METHODS: A systematic literature review was performed in MEDLINE, MEDLINE-In-Process, Embase and the Cochrane Central Register of Controlled Trials databases in April 2015. All English-language full-text published derivation and validation studies for risk prediction models on diabetic outcomes after bariatric surgery were included. Data extraction included population, outcomes, variables, intervention, model discrimination and calibration. RESULTS: Of 2330 studies retrieved, eight met the inclusion criteria. Of these, six presented development of risk prediction models and two reported validation of existing models. All included models were developed to predict diabetes remission. Internal validation using tenfold validation was reported for one model. Two models (ABCD score and DiaRem score) had external validation using independent patient cohorts with diabetes remission assessed at 12 and 14 months respectively. Of the 11 cohorts included in the eight studies, calibration was not reported in any cohort, and discrimination was reported in two. CONCLUSION: A variety of models are available for predicting risk of diabetes following bariatric surgery, but only two have undergone external validation.

Esophagogastric junction distensibility in hiatus hernia.

Hiatus hernia is known to be an important risk factor for developing gastroesophageal reflux disease. We aimed to use the endoscopic functional lumen imaging probe (EndoFLIP) to evaluate the functional properties of the esophagogastric junction. EndoFLIP assessments were made in 30 patients with hiatus hernia and Barrett's esophagus, and in 14 healthy controls. The EndoFLIP was placed straddling the esophagogastric junction and the bag distended stepwise to 50 mL. Cross-sectional areas of the bag and intra-bag pressures were recorded continuously. Measurements were made in the separate sphincter components and hiatus hernia cavity. EndoFLIP measured functional aspects such as sphincter distensibility and pressure of all esophagogastric junction components and visualized all hiatus hernia present at endoscopy. The lower esophageal sphincter in hiatus hernia patients had a lower pressure (e.g. 47.7 ± 13.0 vs. 61.4 ± 19.2 mm Hg at 50-mL distension volume) and was more distensible (all P < 0.001) than the common esophagogastric junction in controls. In hiatus hernia patients, the crural diaphragm had a lower pressure (e.g. 29.6 ± 10.1 vs. 47.7 ± 13.0 mm Hg at 50-mL distension volume) and was more distensible (all P < 0.001) than the lower esophageal sphincter. There was a significant association between symptom scores in patients and EndoFLIP assessment. Conclusively, EndoFLIP was a useful tool. To evaluate the presence of a hiatus hernia and to measure the functional properties of the esophagogastric junction. Furthermore, EndoFLIP distinguished the separate esophagogastric junction components in hiatus hernia patients, and may help us understand the biomechanics of the esophagogastric junction and the mechanisms behind hiatal herniation.

Partial liver ischemia is followed by metabolic changes in the normally perfused part of the liver during reperfusion.

BACKGROUND: Temporary vascular in- and outflow occlusion is an effective technique for bleeding control during liver resection. However, occlusion can result in ischemia/reperfusion (I/R) injury to the liver. The aim of this study in a porcine model was to investigate the effect of in- and outflow occlusion of part of the liver on the metabolism of the normally perfused parenchyma of the same liver measured by microdialysis. METHODS: Eight pigs underwent laparotomy. A microdialysis catheter was inserted into in the left and right part of the liver, respectively. Microdialysis samples were collected every 30 min. Occlusion of the left part of the liver was achieved for 60 min, followed by 5 h of reperfusion. Samples were analyzed for glucose, lactate, pyruvate and glycerol. Blood samples were drawn to determine standard liver and biochemical parameters. RESULTS: Comparing the ischemic part of the liver with the normally perfused part, significant differences in the levels of lactate, pyruvate and glycerol were found. During reperfusion, similar and continuous decreases below baseline levels were observed for lactate and pyruvate in both the ischemic and normally perfused part of the liver. No significant changes in liver parameters or blood glucose levels were seen. CONCLUSIONS: Partial ischemia of the liver is without effects on metabolism in the normally perfused part. Metabolic changes in the ischemic part of the liver were reversible. However, partial liver ischemia was followed by similar continuous decreases in lactate and pyruvate levels in the whole liver, even though the ischemic insult was not detectable in transaminase levels.

Intraductal papillary mucinous tumor of the pancreas (IPMT): follow-up of twelve cases.

INTRODUCTION: Intraductal papillary mucinous tumours (IPMT) were described as a distinct entity in I982. The extent of surgical resection for this disease remains controversial. METHODS: Twelve patients with a diagnosis of IPMT were included in the present retrospective study. RESULTS: Ten out of twelve patients had symptoms suggesting chronic pancreatitis. Two patients were not operated on due to biopsy-verified metastases in the liver. Nine patients were treated with a total pancreatectomy and one with a pancreaticoduodenectomy. In the ten patients operated on for IPMT, histological examination showed eight non-invasive- and two invasive carcinomas. In six cases, multifocal extensive intraductal changes were found, affecting either most of or the whole pancreas. There was no perioperative mortality. Six patients were alive at follow-up without recurrence and four patients were dead, two of them with recurrence. CONCLUSION: IPMTs represent a subgroup of pancreatic neoplasms with a favourable prognosis, and the resection should aim at removing all dysplastic foci. In cases with diffuse dilatation of the main pancreatic duct, widespread tumour involvement of the duct system can be expected and total pancreatectomy should be the operation of choice.

Cytokine changes during warm ischemia and reperfusion of the pig liver with or without preconditioning.

BACKGROUND: Hepatic inflow occlusion results in ischemia-reperfusion injury. The aim of the present porcine study was to investigate whether the pro- and anti-inflammatory cytokine response is involved in mediating the protective effect of ischemic preconditioning (IPC) during, and after warm liver ischemia. METHODS: Fifteen randomized pigs--7 non-IPC and 8 (IPC)--underwent laparotomy followed by 60 min of total ischemia with or without IPC continued by 3 h of reperfusion. Plasma cytokines (IL-6, IL-8, IL-10, and TNF-alpha) were measured during the study period as well as liver parameters (alanine-aminotransferase, alkaline phosphatase, bilirubin, and prothrombin time). RESULTS: In the IPC group, IL-6 increased significantly during reperfusion compared to baseline and the non-IPC group. TNF-alpha increased nonsignificantly in the non-IPC group, while the levels remained stable in the IPC group. IL-8 and IL-10 increased in both groups after reperfusion. Only minor differences were observed in liver parameters. CONCLUSIONS: Warm liver ischemia with or without IPC activates inflammatory cytokines. IL-6 increased significantly in the IPC group compared to the non-IPC group, while the opposite was observed for TNF-alpha. These cytokine changes may be involved in the hepatoprotective mechanism induced by IPC.

Pain in chronic pancreatitis: the role of neuropathic pain mechanisms.

Pain mechanisms in patients with chronic pancreatitis are incompletely understood and probably multifactorial. Recently, evidence from experimental human pain research has indicated that in many of these patients pain processing in the central nervous system is abnormal and mimics that seen in neuropathic pain disorders. The current review focuses on several lines of evidence supporting this hypothesis. Hence, the spontaneous and postprandial pain in chronic pancreatitis may reflect the characteristic pain features seen in patients with neuropathic pain. Biochemical and histopathological findings in tissues from patients with chronic pancreatitis are similar to those observed in patients with other nerve fibre lesions. Experimental studies have shown that patients with chronic pancreatitis show signs of spinal hyper-excitability counter-balanced by segmental and descending inhibition. Changes in the brain with cortical reorganisation to gut stimulation and increased activity in specific electroencephalographic features characteristic for neuropathic pain are also seen in patients with chronic pancreatitis. Finally, principles involved in the treatment of pancreatic pain have many similarities with those recommended in neuropathic pain disorders. In conclusion, a mechanism-based understanding of pain in chronic pancreatitis may have important implications for the treatment.

Effects of 6 months supervised physical training on muscle strength and aerobic capacity in patients undergoing Roux-en-Y gastric bypass surgery: a randomized controlled trial.

Obesity and physical inactivity are major health problems. Roux-en-Y gastric bypass (RYGB) surgery results in significant weight loss and reduces obesity-related morbidity and mortality. Physical activity lowers the risk of cardiovascular disease and premature death. The aims of this study were to elucidate the effects of RYGB followed by 6 months of supervised physical training on physical capacity. In a randomized controlled trial, 60 participants eligible for RYGB were randomized 6 months post-surgery to either two weekly physical training sessions for 26 weeks (INT) or a control group (CON). Aerobic capacity (VO2 max), muscle strength (MS) of the shoulder and hip and physical function were measured pre-surgery and 6, 12 and 24 months post-surgery. RYGB per se decreased MS in all tested muscle groups, had no effects on VO2 max but improved physical function. After the intervention, INT had a significant 0.33 L min-1 increase in VO2 max compared to CON (95% CI: 0.07-0.57, P = 0.013). Furthermore, MS in the hip adductor increased significantly with 13 N (95% CI: 3.6-22.4, P = 0.007) and a between-group difference was found in the Stair Climb Test (0.46 repetitions [95% CI: 0.02-0.91, P = 0.042]). The effects were not maintained at follow-up. Supervised physical training following RYGB improved VO2 max, hip MS and physical function, but the positive effects were not maintained at follow-up. While activities of daily life may become easier as a result of RYGB, the observed extensive post-operative loss of MS requires more attention to increase the patient's physical capacity prospectively.

Risk of peptic ulcer, oesophagitis, pancreatitis or gallstone in patients with unexplained chest/epigastric pain and normal upper endoscopy: a 10-year Danish cohort study.

BACKGROUND: No studies have examined the risk of upper gastrointestinal diseases among patients with unexplained chest/epigastric pain (UCEP) and a normal upper endoscopy. AIM: To examine the relative risk of peptic ulcer, oesophagitis, pancreatitis or gallstone in UCEP patients. METHODS: This Danish 10-year cohort study focused on UCEP patients (n = 386), diagnosed in 1992-93. Ten age- and gender-matched controls were selected per patient from Denmark's Civil Registration System (n = 3860). Kaplan-Meier analysis and Cox's regression analysis was used to calculate the risk of hospitalization for peptic ulcer, oesophagitis, pancreatitis or gallstone. RESULTS: Compared with controls, the adjusted relative risks among UCEP patients <1 and > or = 1 year after upper endoscopy were for peptic ulcer 2.0 [95% confidence interval (CI) 0.2-18.4] and 1.7 (95% CI 0.9-3.4), for oesophagitis 8.2 (95% CI 1.2-59.2) and 1.9 (95% CI 0.7-5.0), for pancreatitis 9.2 (95% CI 2.0-41.8) and 3.9 (95% CI 1.4-10.5), and for gallstone 14.1 (95% CI 5.4-37.2) and 3.3 (95% CI 1.9-5.8). CONCLUSIONS: UCEP is positively associated with all study outcomes especially in the first year after upper endoscopy, indicating that peptic ulcer, oesophagitis, pancreatitis or gallstone could be underlying early UCEP symptoms. However, the long-term association remained strong for pancreatitis and gallstone, suggesting a genuine excess risk.

Endoscopic gallbladder drainage of patients with acute cholecystitis.

BACKGROUND AND STUDY AIM: The standard treatment for acute cholecystitis is early laparoscopic cholecystectomy. In cases of increased operative risk surgery may be postponed or rejected, and instead alternative methods, such as percutaneous or endoscopic drainage, may be attempted. This paper is a retrospective assessment of our results with endoscopic gallbladder drainage (EGBD) by means of endoscopic retrograde cholangiopancreatography (ERCP). PATIENTS AND METHODS: Over a 9-year period, data from all patients who underwent attempted EGBD, primarily referred for diagnosis and treatment of cholestasis by ERCP, were analyzed. EGBD was attempted in those patients who had concomitant acute cholecystitis. RESULTS: EGBD was successful in 24 of 34 patients with acute cholecystitis (70.6%). The success rate rose from 50% during the first 4-year period to 89% during the subsequent 5-year period. Of the 24 patients in whom EBGD had been successful, 21 showed clinical improvement and 10 were finally managed nonoperatively. Of the 21 clinically improved patients, 14 underwent elective surgery a median of 24 days later. Of the 10 patients in whom EGBD failed nine underwent surgery four of whom required surgery within one week. CONCLUSION: Treatment of acute cholecystitis in patients could be done successfully by EGBD, and in 70% of cases cholecystectomy could then be carried out on an elective basis rather than as emergency surgery. Some patients could be treated with EGBD alone. Future prospective trials will clarify the role of EGBD in patients with acute cholecystitis.

Cortical changes to experimental sensitization of the human esophagus.

Topographical organization in the neocortex shows experience-dependent plasticity. We hypothesized that experimental sensitization of the esophagus results in changes of the topographical distribution of the evoked potentials and the corresponding dipole source activities to painful stimulation. An endoscopic method was used to deliver 35 electrical stimuli at the pain threshold to a fixed area of the mucosa in 10 healthy volunteer men and women. The stimulations were repeated after 30 min (reproducibility experiment), and after 60 min following perfusion of 200 ml 0.1 N hydrochloric acid (sensitization experiment). During stimulation the electroencephalogram was recorded from 64 surface electrodes. The sensitization resulted in a decrease in the pain threshold (F=6.2; P=0.004). The topographic distribution of the evoked potentials showed reproducible negative (N1, N2) and positive (P1, P2) components. After acid perfusion a reduced latency and a change in localization was seen for the P1 subdivided into frontal and occipital components (F=29.5, P<0.001; F=53.7, P<0.001). Furthermore the sensitization resulted in a reduction of the latency for P2 (F=6.2, P=0.009). The source analysis showed consistent dipolar activity in the bilateral opercular-insular cortex before and after acid perfusion. For the anterior cingulate dipole there was a reduction in latency (P=0.03) and a posterior shift (P=0.0002) following acid perfusion. The findings indicate that short-term sensitization of the esophagus results in central neuroplastic changes involving the cingulate gyrus, which also showed pathological activation in functional diseases of the gut, thus reflecting the importance of this region in visceral pain and hyperalgesia.

Sensation and distribution of stress and deformation in the human oesophagus.

Evaluation of the distribution of stresses and strains in relation to distension-induced sensation in the human oesophagus is valuable for understanding oesophageal biomechanics and mechano-sensation. In 12 healthy volunteers a specially designed oesophageal bag containing an endoscopic ultrasound probe was inflated to the moderate pain level. Ultrasound images, bag pressure and perceived sensation were recorded before and after pharmacological relaxation of the smooth muscle with butylscopolamine. The oesophagus was assumed to be circular and thick-walled. Distension induced a tensile circumferential stretch, radial compression and longitudinal shortening. Both circumferential strain and stress were highest at the mucosal surface and decreased throughout the wall. The stiffness increased throughout the wall and was highest at the outer surface (P < 0.001). The decrease in stiffness in response to butylscopolamine was non-significant. The infused volume (P = 0.012) and circumferential stress (P < 0.001) were most closely associated with the distension-induced sensation (adjusted R2 = 0.88). The perceived sensation was highly individual but was unaffected by butylscopolamine (P > 0.08). The present study provides a method for computation of the stress-strain distribution throughout the wall and the mechano-sensory interaction in the human oesophagus. In the future, this may be useful for understanding of mechanoreceptor responses and generation of symptoms in visceral organs in health and in disease.

Coagulation, inflammatory, and stress responses in a randomized comparison of open and laparoscopic repair of recurrent inguinal hernia.

BACKGROUND: In previous comparisons of inflammatory and stress responses to open (OR) and laparoscopic (LR) hernia repair, all operations were performed under general anesthesia. Since local anesthesia is widely used for OR, a comparison of this approach with LR seemed relevant. METHODS: Patients with recurrent inguinal hernia were randomized to OR under local anesthesia (n = 30) or LR under general anesthesia (n = 31). The magnitude of the surgical trauma was assessed by measuring markers of coagulation (prothrombin fragment 1 + 2), endothelial activation (von Willebrand factor), inflammation [leukocytes, interleukin-6, -8 and -10, granulocyte macrophage colony-stimulating factor, and C-reactive protein (CRP)], and endocrine stress (cortisol) in blood collected before operation, 4 h postincision, and on postoperative day 2. RESULTS: Leukocyte counts and interleukin-6 and CRP levels increased in both groups, with the CRP increase being significantly greater in the OR group. The other markers did not increase significantly. CONCLUSION: The acute phase response was more pronounced after OR, even when this was done under local anesthesia. Both techniques seemed rather atraumatic.

Electrogastrography in neonates.

BACKGROUND AND AIMS: Procedures for diagnosis of gastrointestinal (GI) symptoms in newborn and preterm infants should preferably be non-invasive. This study evaluates the usability of electrogastrography (EGG), a non-invasive, cutaneous recording of the gastric myoelectrical activity in newborn infants. METHOD: Sixty-two randomly selected infants [27 girls and 35 boys with median gestational age of 36 weeks (range 29-42)] divided into six groups (by postconceptional age) were studied on median day 5 (range 1-24) after birth. None had GI symptoms. EGG recordings were made by Digitrapper EGG recording system. RESULTS: Findings were highly dispersed and without statistical difference both between pre- and postprandial periods and among the six study groups. Dominant frequency of 2.5 cycles per minute was found for 57 of 62 infants, with distribution of normal, bradygastric and tachygastric slow wave frequency uniformly dispersed around 50, 35 and 15% respectively. CONCLUSION: We find EGG unsuitable for clinical use because of significant variation in gastric slow wave frequency in normal term and preterm infants without GI symptoms.

A comparative study of skills in virtual laparoscopy and endoscopy.

BACKGROUND: The present study was designed to investigate whether there is a correlation between manual skills in laparoscopic procedures and manual skills in flexible endoscopy. METHODS: In a prospective study using laparoscopy and endoscopy simulators (MIST-VR, and GI-Mentor II), 24 consecutive subjects (gastrointestinal surgeons, novice and experienced gastroenterologists, and untrained subjects) were asked to perform laparoscopic and endoscopic tasks. Their performance was assessed by the simulators' software and by observers blinded to the levels of subjects' experience. Performance in experienced vs inexperienced subjects was compared. Score pairs of three parameters--time, errors, and economy of movement--were also compared. RESULTS: Experienced subjects performed significantly better than inexperienced subjects on both tasks in terms of time, errors, and economy of movement (p < 0.05). All three performance parameters in laparoscopy and endoscopy correlated significantly (p < 0.02). CONCLUSION: Both simulators can distinguish between experienced and inexperienced subjects. Observed skills in simulated laparoscopy correlate with skills in simulated flexible endoscopy. This finding may have an impact on the design of training programs involving both procedures.

Module based training improves and sustains surgical skills: a randomised controlled trial.

PURPOSE: Traditional surgical training is challenged by factors such as patient safety issues, economic considerations and lack of exposure to surgical procedures due to short working hours. A module-based clinical training model promotes rapidly acquired and persistent surgical skills. METHODS: A randomised controlled trial concerning supervised hernia repair in eight training hospitals in Denmark was performed. The participants were 18 registrars [Post graduate year (PGY) 3 or more] in their first year of surgical specialist training. The intervention consisted of different modules with a skills-lab course followed by 20 supervised Lichtenstein hernia repairs. Operative performance was video recorded and blindly rated by two consultants using a previously validated skills rating scale (8-40 points). Outcome measures were change in the ratings of operative skills and operative time. RESULTS: In the intervention group (n = 10) the average rating of operative skills before intervention was 22.5 (20.6-24.3) and after 26.2 (23.5-28.8), p = 0.044. At follow-up after 1 year, rating was 26.9 (23.4-30.4), p = 0.019. In the conventionally trained group average rating was 23.4 (19.4-27.3) at start and 21.7 (17.3-26.1) at end, p = 0.51. At start no difference was detected between the two groups, p = 0.59; by 1 year the difference was statistically significant favouring intervention, p = 0.044. Operative time showed similar results in favour of the intervention. CONCLUSIONS: A module-based training model in Lichtenstein hernia repair was preferable in both short and long-term compared with standard clinical training. The model will probably be applicable to other surgical training procedures.

Identifying responders to acid suppression in dyspepsia using a random starting day trial.

BACKGROUND: Functional dyspepsia is a heterogeneous condition and a uniform response to drug treatment is not likely. This may be the reason for the general failure of acid suppression in clinical trials in these patients. It may be more rewarding to identify true responders to drug treatment by a single subject trial. AIM: To develop and to test a novel single subject trial design (random starting day trial) in dyspeptic patients. PATIENTS AND METHODS: A total of 301 dyspeptic patients entered a 16-day trial. All patients received placebo for the first 4 days and switched to omeprazole at a randomized and blinded day between day 5 and day 14. Response was defined as a sustained >/= 50% decrease in symptom score occurring in relation to drug shifting. RESULTS: Spontaneous response varied between 0.3% and 10.6% per day, uniformly distributed over time. Overall, 53-61% of patients with organic dyspepsia had a symptom response in relation to shifting to active treatment, compared to only 23% of patients with functional dyspepsia. The only predictor of response was symptoms suggesting gastro-oesophageal reflux. CONCLUSIONS: A random starting day trial may be a valuable tool to identify response to acid suppression in dyspeptic patients.

The effect of vagotomy on human gastroesophageal sphincter pressure in the resting state and following increases in intra-abdominal pressure.

The effect of surgical isolation and extrinsic denervation of the distal 5 to 7 cm of the human esophagus on resting gastroesophageal sphincter pressure and its response to graded increases of external abdominal compression was determined in 89 patients with duodenal ulcer. Fasting serum gastrin concentration also was measured. No significant changes in resting sphincter pressure were obtained before and after vagotomy of various types: parietal cell vagotomy, selective gastric vagotomy plus drainage, and selective gastric vagotomy plus precise antrectomy. No correlation between resting sphincter pressure and fasting serum gastrin concentration was found in any of the groups studied. The increase in gastroesophageal sphincter pressure was similar to the increase in intragastric pressure after 10, 20, and 30 mm Hg of external abdominal compression and was unchanged after all types of vagotomies. These results suggest that (1) extrinsic innervation of the lower esophageal sphincter in humans does not regulate the resting tone of the sphincter; (2) extrinsic "mechanical" influence does not play any role in the maintenance of resting pressure; (3) the effect of increased abdominal pressure is a pure mechanical effect, is unchanged after vagotomy, and therefore is not regulated by external neural reflex.

Increased serum pancreatic polypeptide and serum gastrin secretion in patients with functional dyspepsia: correlation to the shape of the duodenal loop.

Simultaneous measurement of food-stimulated serum pancreatic polypeptide and serum gastrin was carried out in 18 patients with functional dyspepsia and correlated to the shape of the duodenal loop. Significantly higher serum concentrations of pancreatic polypeptide and gastrin were encountered in patients with an abnormal shape of the duodenal loop compared to patients with a normal shape. Although no cause could be given to the phenomenon it may be taken into account when evaluating hormone profiles in patients with functional dyspepsia.

Gastric emptying patterns of a liquid meal in newborn infants measured by epigastric impedance.

Epigastric impedance was used to measure the gastric emptying patterns of a liquid non-caloric meal (5 mL water kg-1) in 30 healthy newborn infants. Twenty-six mature infants were examined in the first eight days of life, and four preterm infants were examined within 6 weeks after birth. The recordings consisted of two components: the emptying signal (the DC component), and a phasic 3 cycles per minutes (CPM) signal (the AC component). In some of the infants the phasic 3 CPM signal was also seen during the fasting state. For mature infants the median half emptying time (T50) was 6.9 min. For a second meal given within one hour after the first meal the half emptying time was 5.5 min (P < 0.01). In preterm infants the emptying times were not significantly different from mature infants. Day-to-day variation was low with a coefficient of variation of 17% in nine infants. A periodic change of the impedance signal, the phasic 3 CPM signal, was observed after a meal in 24 of the infants. The median frequency was 3.0 CPM in 20 mature and 2.9 CPM in four preterm infants. In nine infants a phasic 3 CPM signal was also observed during the fasting state, with a median frequency of 2.9 CPM. Measurement of gastric emptying pattern with epigastric impedance is a simple investigation for the evaluation of gastric emptying time and phasic activity in mature and preterm infants. However, the method is sensitive to spontaneous movements of the children, resulting in non-valid measurements in around one fourth of the infants.

Bile duct injury during laparoscopic cholecystectomy: a prospective nationwide series.

BACKGROUND: The risk of bile duct injury in laparoscopic cholecystectomy has been a concern since the procedure became part of the surgical armamentarium. Our study assesses the incidence, types, and treatment for laparoscopic bile duct injury. STUDY DESIGN: Prospective case registration in a national database with participation by all departments of surgery performing laparoscopic cholecystectomy in Denmark since the first operation in January 1991. The case notes for bile duct injury have been reviewed. RESULTS: From 1991 through 1994, 57 of 7,654 patients sustained bile duct injury (0.74 percent; 95 percent confidence interval, 0.55 percent to 0.94 percent), including nine injuries occurring after conversion. The annual incidence did not decrease. Thirty-nine percent of the laparoscopic bile duct injuries were incisions, 39 percent were transections, and 12 percent were clip injuries or strictures. One patient, who sustained transection during open reoperation for bleeding after a converted procedure, died. Bile leaks for reasons other than bile duct injury occurred in 2.1 percent; 71 percent of these were cystic duct leaks. Acute cholecystitis was the indication for laparoscopic cholecystectomy in 968 patients, with 1.3 percent sustaining laparoscopic bile duct injury (95 percent confidence interval, 0.62 percent to 2.08 percent), while the incidence in patients with other indications for laparoscopic cholecystectomy was 0.62 percent (95 percent confidence interval, 0.44 percent to 0.82 percent) (p > 0.05). Preoperative knowledge of bile duct anatomy was available by means of preoperative endoscopic retrograde cholangiopancreatography or intravenous cholangiography in 26 percent of patients undergoing laparoscopic cholecystectomy but this did not reduce the risk of bile duct injury. The frequency of bile duct injury in patients who had intraoperative cholangiography was not significantly different from those who did not. Intraoperative cholangiography was done in 14 cases of injury (diagnostic for injury in 8, misinterpreted in 2, and normal in 4 patients). The case notes described operative difficulties in 11 of 48 cases of laparoscopic bile duct injury, most often because of fibrosis or difficulty delineating the anatomy. CONCLUSIONS: The incidence of bile duct injury in laparoscopic cholecystectomy is higher than previously generally anticipated and did not decrease from 1991 through 1994. Risk factors and possible preventive measures should be evaluated in prospective studies.